Provo • Relatives of two Utah teenagers who were killed and dumped in an abandoned mine shaft are calling for prosecutors to pursue the death penalty against the man charged in their deaths.

Jerrod Baum pleaded not guilty Monday to aggravated murder and other charges in the deaths of 17-year-old Brelynne "Breezy" Otteson and 18-year-old Riley Powell.

Relatives of the victims said they were not surprised by the plea.

“We knew a long time ago he was going to plead not guilty,” Bill Powell, Riley Powell’s father, told KSL-TV. “He’s that kind of person. He won’t own up to what he did. He’s a chicken.”

The teens were missing for nearly three months before their bodies were found in the mine shaft near Eureka in March 2018.

Morgan Henderson testified earlier this year that Baum, 42, stabbed the two teens after tying them up and driving them to the mine. Her former boyfriend was upset that the teens had visited her, she said. She pleaded guilty to 10 counts of obstruction of justice and agreed to cooperate with authorities.

Bill Powell and Amanda Hunt, the aunt of Otteson, said they want prosecutors to seek the death penalty.

"Their lives were taken from them, and he shouldn't get the right to be able to live," Hunt said.

Utah County Attorney David Leavitt said the death penalty is a possibility, but prosecutors are still examining evidence and factors in the case. The family will be factored into the decision, he said.

"Really, what the family wants is to have their family members back," Leavitt told the Daily Herald . "That will never happen. They know that, and we're forming a very good relationship between the police, the prosecution team and the families."

Baum is scheduled to appear in court for a pretrial hearing on Aug. 12.